1. Field of the Invention
The present invention relates generally to systems for the filling, transport, and emptying of liquid containers. More particularly, the invention concerns a novel, tamper-proof, safety valve system that includes a tamper evident valve closure cap that must be broken before liquid can be removed from the container.
2. Discussion of the Prior Art
For many years numerous types of liquids were stored and transported in throw-away type metal and plastic containers. Typically, such containers were provided with a threaded liquid outlet port which after the container was filled, was closed by some type of threaded cap. The use of these types of containers was costly, inefficient and often hazardous, particularly when the containers were used to store and transport potentially dangerous chemicals.
In recent years substantial efforts have been made to develop new systems to improve container and drum management capabilities, minimize user exposure to hazardous materials and address emerging governmental regulations. These efforts have resulted in the development of several different types of reusable systems for transferring liquid formulations from returnable closed drums and containers and for providing means for guarding against potentially dangerous system tampering. As a general rule, these systems to a greater, or lessor extent, simplify drum emptying, minimize operator hazards, improve cleanliness and eliminate costly waste inherent in prior art disposable container systems. One of the most advanced of such improved systems was developed by and is presently commercially available from Micro Matic, Inc. of Northridge, Calif.
The Micro Matic system is basically a two-part system which comprises a coupler operated extractor valve which is interconnectably with a conventional drum via existing threaded connections and a cooperating coupler which connects to the extractor valve to allow drum emptying through the use of a separate pumping system. The extractor valve apparatus which can either remain with the drum after emptying, or can be removed for drum processing, includes a valve body and a down tube connected to the valve body which extends to the bottom of the drum to permit the complete transfer of liquid from the drum. To guard against tampering, the Micro Matic system includes tear-away type closure cap which covers the access port of the valve body when the coupler is separated from the system.
The Micro Matic system, while representing the best of the current state of the art liquid transfer systems, has certain drawbacks which are sought to be overcome by the system of the present invention. By way of example, unlike the prior art Micro Matic system, the novel system of the present invention provides for the first time, a customer unique, key type coupler mating interface and includes a safety closure cap which, unlike the tear away type closure cap of the prior system, can be completely removed from valve body in one simple step. Other improvements and advantages of the present system over the present art systems will be described in greater detail in the paragraphs which follow.